Dave visits with legendary United States Geological Survey volcanologist Donald Swanson in this look back at the eruption of Mt. St. Helens on May 18, 1980. Preceded by weeks of earthquakes and minor eruptions, Mt. St. Helens exploded in violent fury on that fateful spring morning in the Pacific Northwest, taking 57 lives and devastated millions of cubic meters of timber, killed thousands of big game animals, destroyed 250 homes and wiped out hundreds of miles of highway.